Fabiola Paciello1, Maria Vittoria Podda2, Rolando Rolesi3, Sara Cocco4, Laura Petrosini5, Diana Troiani4, Anna Rita Fetoni6, Gaetano Paludetti7, Claudio Grassi8. 1. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy; Institute of Cell Biology and Neurobiology, CNR, 00015, Monterotondo Scalo, Rome, Italy. 2. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Rome, Italy. Electronic address: MariaVittoria.Podda@unicatt.it. 3. Institute of Otolaryngology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Rome, Italy. 4. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy. 5. Department of Psychology, University Sapienza of Rome and IRCCS Santa Lucia Foundation, 00179 Rome, Italy. 6. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy; Institute of Otolaryngology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Rome, Italy. Electronic address: AnnaRita.Fetoni@unicatt.it. 7. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy; Institute of Otolaryngology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Rome, Italy. 8. Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Rome, Italy.
Abstract
BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive tool capable to modulate cortical functions by affecting neuronal excitability and synaptic plasticity. OBJECTIVE: Here we investigated the effects of anodal tDCS on auditory cortex (ACx) in normal-hearing rats and following a paradigm of noise-induced hearing loss (NIHL), that causes morphological alterations in ACx pyramidal neurons. METHODS: Male rats exposed to intense pure tone (10 kHz) were subsequently subjected to unilateral anodal tDCS of ACx and changes in dendritic morphology and spines were assessed by Golgi-Cox staining 30 days after the onset of the acoustic trauma. Molecular and functional changes were investigated by Western immunoblotting, immunofluorescence experiments and electrophysiological recordings in brain slices. RESULTS: We found that NIHL altered dendritic morphology by decreasing spine density, mostly in layer 2/3 pyramidal neurons. Interestingly, tDCS increased ACx spine density, targeting apical dendrites of layer 2/3 and 5/6 pyramidal neurons in rats with normal auditory function and both apical and basal arborizations in layer 2/3 of NIHL rats. Twenty-four hours after tDCS, Bdnf and synaptophysin levels in ACx increased both in normal-hearing and noise-exposed rats. Field recordings showed that basal synaptic transmission at layer 2/3 horizontal connections was significantly reduced in noise-exposed rats compared to normal-hearing animals and, notably, input-output curves of noise-exposed animals subjected to tDCS were similar to those of normal-hearing rats. CONCLUSIONS: Our findings provide novel evidence that anodal tDCS affects structural plasticity in the ACx suggesting that it might be beneficial in treating cortical alterations due to cochlear damage.
BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive tool capable to modulate cortical functions by affecting neuronal excitability and synaptic plasticity. OBJECTIVE: Here we investigated the effects of anodal tDCS on auditory cortex (ACx) in normal-hearing rats and following a paradigm of noise-induced hearing loss (NIHL), that causes morphological alterations in ACx pyramidal neurons. METHODS: Male rats exposed to intense pure tone (10 kHz) were subsequently subjected to unilateral anodal tDCS of ACx and changes in dendritic morphology and spines were assessed by Golgi-Cox staining 30 days after the onset of the acoustic trauma. Molecular and functional changes were investigated by Western immunoblotting, immunofluorescence experiments and electrophysiological recordings in brain slices. RESULTS: We found that NIHL altered dendritic morphology by decreasing spine density, mostly in layer 2/3 pyramidal neurons. Interestingly, tDCS increased ACx spine density, targeting apical dendrites of layer 2/3 and 5/6 pyramidal neurons in rats with normal auditory function and both apical and basal arborizations in layer 2/3 of NIHL rats. Twenty-four hours after tDCS, Bdnf and synaptophysin levels in ACx increased both in normal-hearing and noise-exposed rats. Field recordings showed that basal synaptic transmission at layer 2/3 horizontal connections was significantly reduced in noise-exposed rats compared to normal-hearing animals and, notably, input-output curves of noise-exposed animals subjected to tDCS were similar to those of normal-hearing rats. CONCLUSIONS: Our findings provide novel evidence that anodal tDCS affects structural plasticity in the ACx suggesting that it might be beneficial in treating cortical alterations due to cochlear damage.
Authors: Marom Bikson; Zeinab Esmaeilpour; Devin Adair; Greg Kronberg; William J Tyler; Andrea Antal; Abhishek Datta; Bernhard A Sabel; Michael A Nitsche; Colleen Loo; Dylan Edwards; Hamed Ekhtiari; Helena Knotkova; Adam J Woods; Benjamin M Hampstead; Bashar W Badran; Angel V Peterchev Journal: Brain Stimul Date: 2019-07-17 Impact factor: 8.955
Authors: Sara Cocco; Marco Rinaudo; Salvatore Fusco; Valentina Longo; Katia Gironi; Pietro Renna; Giuseppe Aceto; Alessia Mastrodonato; Domenica Donatella Li Puma; Maria Vittoria Podda; Claudio Grassi Journal: Front Cell Dev Biol Date: 2020-07-03
Authors: Walter Di Nardo; Tiziana Di Cesare; Angelo Tizio; Gaetano Paludetti; Anna Rita Fetoni Journal: Front Neurosci Date: 2022-06-24 Impact factor: 5.152